Bug 1216386 - Improve AnimatedGeometryRootLookup::Hash. r=roc.

When someone types |sizeof(this)| they usually want |sizeof(*this)|.

--HG--
extra : rebase_source : 5bcb9908bb22a60824c875fec8d699ca1bba7c48

layout/base/nsDisplayList.h

@@ -1113,7 +1113,7 @@ private:
     }
 
     PLDHashNumber Hash() const {
-      return mozilla::HashBytes(this, sizeof(this));
+      return mozilla::HashBytes(this, sizeof(*this));
     }
 
     bool operator==(const AnimatedGeometryRootLookup& aOther) const {